Lens finishing machine



June 30, 1953 K. c. BURROUGHS 2,643,490

LENS FINISHING MACHINE Filed Dec. 5, 1950 2 Sheets-Sheet 1 INVENTOR. KENNETH C. BU R ROUGHS ,9 Tram/5K5 June 30, 1953 c, BURROUGHS 2,643,490

LENS FINISHING MACHINE Filed Dec. 5, 1950 2 Sheets-Sheet 2 INVENTOR. KENNETH C. BU R ROUG HS A a I l Patented June 30, 1953 LENS FINISHING MACHINE Kenneth C. Burroughs, Plainville, Mass, assignor to Burroughs Optomat, Inc., New York, N. Y., a corporation of Massachusetts Application December 5, 1950, Serial No. 199,337

3 Claims.

This invention relates to lens finishing and particularly to a machine for carrying out the polishing operations after the lens has had the desired curvature generated thereon.

In the manufacture of glass lenses for optical uses, such as in spectacles, the lenses may be formed to the proper curvature in various manners. After a lens has been ground, the final operation usually comprises a polishing operation wherein rouge cerium oxide or other abrasive is employed in conjunction with a suitable tool brought into contact with the rotating blank. It is desirable in many instances to oscillate the axis of the tool relative to a rotating lens blank rotating on a fixed axis. Accuracy is of prime importance in quantity production manufacture of lenses so that all elements of the machines used must be constructed so as to eliminate errors, particularly those which might be caused by wear of the parts. It also is desirable to be able to adjust the various parts of the machines with ease and accuracy.

One of the objects of this invention is to provide an improved oscillating mechanism and arrangement for a lens polishing or finishing machine.

In one aspect of the invention, a plurality of polishing tool spindles are employed in each unit or frame, preferably four. Of course, there may .be more or less arranged on a frame as desired. The unit frame and operating parts for the work spindles, for example, may be similar to those described generally in applicants copending application Serial No. 199,335 filed December 5, 1950.

Each of the work blank spindles may be driven and may be axially movable into contact with the polishing tool. Preferably, a work blank spindle is raised by means of mechanism having a yieldable connection so that each spindle can be brought to a fixed stop regardless of over travel of the raising mechanism. Thus, by such an arrangement, each work spindle can be adjusted to move to the correct position relative to its tool. Each polishing tool is held by a rotatable tool spindle and air or spring pressure employed to urge the spindle and tool toward a blank to provide a desired surface pressure on the lens to be polished. The spring pressure arrangement shown in applicant's copending application Serial No. 199,336 filed December 5, 1950, preferably is used. The tool itself may be a shaped disc universally mounted on the rotatable tool spindle. Preferably, the tool is smaller in diameter than the lens.

Each tool spindle head is carried on an oscillatable frame mounted on a shaft means carried by the main machine frame. A connecting link is arranged to be carried by spaced arm means, said arm means being pivotally carried by said frame shafts or serving as a bearing for one end of said shaft means. The arm means are oscillatable relative to their shaft means and are not connected therewith. Suitable adjustable connections are provided between each of the tool head frame means and the link means.

As a result of the construction and arrangement of the invention, the relative oscillating movement between the arm and the shaft will be small and wear will be minimized. Furthermore, the arrangement can be easily adjusted.

These and other objects, advantages, and features of the invention will become apparent from the following description and drawings which are merely exemplary.

In the drawings:

Figure l is a fragmentary rear View of the upper part of a machine employing the present invention.

Figure 2 is a reduced fragmentary schematic top view of the arrangement of Figure 1.

Figure 3 is an enlarged fragmentary view of one of the tools and a work blank.

Figure 4 is an enlarged fragmentary View partially in section of a tool head frame.

Figure 5 is a fragmentary enlarged view of one form of spring pressure arrangement.

The invention will be described in conjunction with a four-spindle machine, but it is to be understood that it may be used with a greater or lesser number of spindles, there being at least two involved.

Each of the tool spindles may be mounted in a tool spindle head [0 carried by the spindle head frame H. Each spindle frame II is mounted on a shaft means l2 which may extend through the frame or may merely comprise end shaft members. The front end of each shaft means I2 is carried in a suitable bearing l2 at the front end of the machine frame. The rear journals or bearings for the shafts [2 are located at the rear of the machine frame ll.

Link carrying arms l5, I5 are located at spaced positions relative to each other, the hubs I4 of arms [5, I5 being carried on the ends of appropriate shaft means 12. Thus, the hubs Id of the arms [5, l5 are oscillatable relative to shaft means [2, shaft means [2 being oscillatable in its bearing It. It can be seen that the relative movement between hub M and shaft means 12 .will be small, inasmuch as they will be movin in the same direction throughout almost all of their movement.

Link bar It is connected to the various tool head frames by means of slots I9 therein receiving rollers 20. Rollers 2% are attached to the link I8 by bolts or stud members 2!, said bolts being adjustable longitudinally of link H3 in link slots 22.

A bracket 23 is fastened at 24 to link l8 and is pivotally attached to arm I5 by bolt 25. Bracket 26 is fastened to the link I8 at 21 and to arm I5 by bolt 28. The extension 29 is connected at 30 to the rod 3|, said rod being adjustably connected to the eccentric 32 at 33. Motor is employed to drive the eccentric, operation of motor 34 serving to reciprocate link I8, which in turn will oscillate the various tool heads, link I8 being carried by arms I5 and I5.

The spindle head I9 (Figure 3) can carry a rotatable plate or support 35 to which is attached tool 36, said tool 36 being mounted thereon by means of a universal link 3'! so that the tool can move universally in following the lens surface.

Lens blank 38 is carried by a blank holder 39, which in turn is held by the rotatable and axially reciprocable work spindle 49. The blank holder has a tapered aperture therein fitting a tapered end of the work spindle so as to position the work holders predeterminedly thereon.

The work spindle is raised to a fixed stop which is adjusted so that the lens blank is in contact with tool 36. The tool 36 preferably is urged downwardly by a spring (not shown) against the work. The spring force mechanism may be similar to that illustrated in copending application Serial No. 199,336. As the work spindle is rotated, the tool will rotate and will be oscillated. It is possible to positively drive the tool by moun ing an appropriate motor on the frame II.

One form of spring mechanism is seen in Figure 5 wherein tool spindle holder I26 can be mounted on an arm IIO (Fig. 3), tool spindle holder I35 having a spring I36 located between the upper surface of member I33 and the plate I35 of the holder I35. Spring arrangement 131 can be provided for applying spring pressure downwardly and thereby furnishing pressure on the tool relative to the lens surface when in contact therewith during the finishing. Spring I38 is located in holder body I39, the spring urging member I49 outwardly, member I having a ball element MI through which force is transmitted to spindle I35. Spindle I35 is rotatable relative to spring holder I39 ball element I 4| permitting such movement.

Plug I42 is screw-threadedly engaged in holder I39, said plug providing an upper abutment for spring I38. The plug I42 also can have attached thereto a leaf latch spring I43, said latch spring having an aperture I94 therein through which stem I connected with member I40 passes.

Air operated release latch M6- is located in a suitable aperture in plug I42, the latch having an aperture I41 therein reciprocally receiving the upper end of plunger I45 where pressure may be introduced at appropriate times through opening I49. As the latch release I46 is moved downwardly, it will contact leaf latch I43 and straighten it out relative to stem I45, thus releasing its grip upon the stem so as to permit spring I38 to act against member I49 and thus urge the tool toward the work. The tool 36 of Fig. 3 can be suitably fastened to the end A of the spindle of Figure 5.

It is to be understood that details of construction can be varied without departing from the spirit of the invention except as defined. 1n the appended claims.

What is claimed:

1. In a lens finishing machine or the like having a plurality of rotatable finishing tool heads and spindles and a plurality of work spindles oooperable therewith for carrying work in contact with said tools, the combination including a main supporting means, a plurality of oscillatable frame means holding each of said tool heads, finishing tools rotatably mounted on each of said tool heads, a plurality of shaft means mounted on said machine main supporting means and rotatably carrying each of said oscillatable frame means, a reciprocable link means adjustably connected to at least some of said frame means for oscillating the same, driving means connected to said link means for reciprocating the same, oscillatable link carrying arm means pivotally mounted on at least two of said shaft means, and connections between each of said arm means and said link means supporting said link, said oscillatable arm means being relatively rotatable relative to the shaft means upon which it is mounted for oscillating each tool relative to its work piece.

2. In a lens finishing machine or the like having a plurality of finishing tool heads with rotatable tools spindles thereon and a plurality of work spindles cooperable therewith, the combination including a main machine support means, on oscillatable frame means for each of said tool heads and upon which the head is mounted, aplurality of pivoted shaft means mounted on said main machine support means carrying each of said oscillatable frame means, reciprocable link means, adjustable means connecting said link means to each of said oscillatable frame means, driving means connected to said link means for reciprocating the same, link carrying oscillatable arm means pivotally mounted on each of said shaft means, and connections between each of said arm means and said link means carrying said link means, said arm means being relatively rotatable relative to the shaft means upon which it is mounted.

3. In a lens finishing machine having a plurality of finishing tool heads and spindles with rotatable tools on each spindle and a plurality of work spindles cooperable therewith and movable so as to bring the tool and work into contact, the combination including a main machine frame, oscillatable frame means for each of said tool heads, said tools being mounted upon said tool heads, a plurality of shaft means mounted on said machine pivotally carrying each of said oscillatable frame means, reciprocable link means, adjustable means connecting said link means to each of said oscillatable frame means including a roller and slot connection therebetween, driving means connected to said link means for reciprocating the same, oscillatable link carrying arm means pivotally mounted on two of said shaft means, and connections between said link carrying arm means and said link means supporting said link means, said arm means being rotatable relative to each of the shaft means supporting the same.

KENNETH C. BURROUGHS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 930,639 Woodruif Aug. 10, 1909 1,639,012 lillyer et al. Aug. 16, 1927 2,402,865 Andersen June 25, 1946 2,403,341 Carlson July 2, 1946 2,419,543 Ellis et. al. Apr. 29, 1947 

